1. Field of Invention
The present invention relates in general to a display method, and more particular, to a display method operative to perform full-color display based on integration of various colors of backlight without using color filters.
2. Related Art
The fast developments of media are basically benefited by the advancement of semiconductor devices and human-machine display apparatus. For the display market, the cathode ray tube used to dominant products because of the high display quality and the economic value. However, the growth of personal desktop terminal/display has raised great environmental and power saving concerns. The power consumption and large size of the cathode ray tube gradually caused the displays based thereon replaced by the light, thin, short, small, low power consumed, and radiation-free liquid crystal displays.
Referring to FIGS. 1 and 2, the liquid crystal display 100 includes a backlight module 110 and a liquid crystal panel 120. The liquid crystal panel 120 is mounted on the emerging surface 112 of the backlight module 110. The liquid crystal panel 120 includes an active device array substrate 130, a color filter substrate 140 and a liquid crystal layer 150 sandwiched between the active device array substrate 130 and the color filter substrate 140. The picture displayed by the liquid crystal display is constructed by an array of pixels 160 each is arranged with three sub-pixels in the form of red, green and blue color thin-films 162, 164 and 166. The color displayed by each of the pixels 160 is determined by the light emitted by the backlight module 110 and propagating through the color thin-films.
In the current display methods of liquid crystal display, the array technique is the most commonly used. The array technique uses a backlight module 110 to provide white light W filtered by the color thin-films of the sub-pixels 162, 164 and 166 into red light, green light and blue light. By controlling the twisting angles of the liquid crystal molecules, the transmission rates of the sub-pixels 162, 164 and 166 for each pixel 160 can thus be adjusted to provide a resulting color mixed by various intensities of red light, green light and blue light. Referring to FIG. 3, the x-axis indicates the spatial ratio of each color image, and y-axis indicates the frame time ratio of each image. As shown in the conventional display method, each color thin-film occupies ⅓ of each pixel, such that the spatial utility for each color image is limited to ⅓.
To resolve such issue, a color sequential display method has been proposed. In the liquid crystal display using color sequential method, the cold cathode fluorescent lamp (CCFL) of the backlight module is operative to emit red, green and blue color light without using the color thin films, and the three primary lights can be switched quickly. The vision persistence of human eyes and the high frequency switching speed of the cold cathode fluorescent lamp between three primary colors allow the human to visualize full color picture. Referring to FIG. 4, the x-axis indicates the spatial occupancy of each color image, and the y-axis indicates the occupancy of each color image in each unit frame time. As shown in FIG. 4, to provide a fluent frame (for example, to have the same length of unit frame time of the conventional array method), the scan frequency of the liquid crystal display using the color sequential method is three times of that required by the liquid crystal display using array method. The complexity for fabricating such type of liquid crystal display is thus three times of that for the liquid crystal display using array method.